Linkwork



June ZZ, 1965' J, HAl RDAKER ETAL 3,190,143

LINKWORK Filed Feb. 23, 1962 v 2 Sheets-Sheet 1 LINKWORK 2 Sheets-Sheet 2 Filed Feb. 25, 1962 ?atented June 22, 1965 3,190,143 A LINKWORK John Hardaker, Woking, Surrey, and Richard Rowland Evans, Barnes, London, England, assiguors' to Her Britannic Majestys Principal Secretary of State for the This invention relates to linkwork and has for its object to compensate for errors in the transmission of movement therethrough dueto difierent parts thereof being subjected to different and varying temperature conditions such, for example, as may be experienced when one part of the linkwork is located in a casing or container and the other part is arranged exteriorly of such casing or container andis exposed to considerably diflerent temperature conditions. Such variations of temperature condi tions normally cause difierent parts of the linkwork to expand at different rates and this to affect the transmission either in extent or in phaseor in both extent and phase.

According to this invention a linkwork having co-acting links that are normally subjected to different and varying temperature conditions has at least one of the links of tubular form which is arranged in a fluid circuit,

the temperature of the fluid flowing in the circuit being tion of the invention to a gun and sighting apparatus carried by an armored vehicle, and

FIGURE 2 is a perspective view of a linkwork diagrammatically illustrated in FIGURE 1.

As shown in the drawings a a parallelogram linkage connects the trunnions 1 of a gun 2 mounted in an armored vehicle and the trunnions 3 of a sighting apparatus 4 for the gun which sighting apparatus is located remotely from the gun trunnions. Such linkwork consists of two arms 5, 6, respectively keyed to and extending radially from a gun trunnion or an extension thereof and one of the trunnions upon which the sighting apparatus of the gun is pivotally supported, which arms are connected by a tubular link or rod 7. The ends of the tubular link or rod are sealed, but adjacent the ends thereof are nipples or connectors 8, 9 for insertion into tubing. The fourth side of the parallelogram linkwork is usually formed by part of the body 10 of the vehicle. Secured to or formed integrally with the body of the vehicle, and suitably located, e.g. adjacent the sighting apparatus, is a tank or reservoir 11 for liquid. A pump 12 is also provided. The nipple or connector 8' at one end of the tubular link or rod is connected by tubing 13 to the tank or reservoir and the nipple or connector 9 at the other end of the said tubular link or rod is similarly connected by tubing 14 to the pump 12, the circuit being completed by connecting the-pump 12 to the'tank or reservoir 11 by tubing 15. An expansion chamber 16 or a header tank is associated with the tank or reservoir, which chamher also allows air to be bled from the tank or reservoir so that it can be completely filled with liquid which may be in intimate contact with the body of the vehicle.

Liquid is circulated by the pump 12 through the tank or reservoir 11 and the tubular link or rod 7 and the temperature of the liquid is varied in accordance with the temperature of the body of the vehicle due to sunshine, rain or other weather conditions to which it is subjected. By circulation of the liquid the temperature of the tubular link or rod 7 is maintained substantially similar to that of the'body of the vehicle and in consequence the distance between the trunnions of the gun and the sighting apparatus and the length of the tubular link or rod will be maintained substantially equal.

In cases where 'all the links of a linkwork consist of rods, these may all be, tubular and so connected together thatliquid can be circulated through all of the 1; A linkwork comprising co-acting links that are normally subjected to different andvarying temperature conditions, at least one of said links being solid in cross section and atleast one of said links being tubular in cross section, a reservoir vessel located in the same ambient environment as a link solid in cross ,section' so that the temperature of the vessel is in substantial equilibrium with that of said link solid in cross section, pump means, and conduit means connecting said vessel, tubular link and pump to form a closed circuit for the flow of fluid therethrough.

2.-A linkwork comprising a tubular link and a coacting link which are normally subjected to diiferent and varying temperature conditions, reservoir means subjected to substantially the same temperature conditions as said co-acting link, conduit means interconnecting said reservoir means and said tubular link, and means to circulate fluid in a closed circuit from said reservoir means through said tubular link to maintain said links at substantially the same temperature.

3. A linkwork according to claim 2 wherein said means to circulate fluid comprises a pump.

4. A linkwork including a fixed link, a tubular link disposed parallel thereto and spaced therefrom by connecting arms disposed adjacent each end of said tubular link, reservoir means disposed to be subjected to substantially the same temperature conditions as said fixed link, first conduit means interconnecting said reservoir References Cited by theExaminer UNITED STATES PATENTS 1,945,512 2/34 Bijur 74-587 XR 2,907,415 10/59 Norman 74586 XR BROUGHTON G. DURHAM, Primary Examiner. DON A. WAITE, Examiner. 

1. A LINKWORK COMPRISING CO-ACTING LINKS THAT ARE NORMALLY SUBJECTED TO DIFFERENT AND VARYING TEMPERATURE CONDITIONS, AT LEAST ONE OF SAID LINKS BEING SOLID IN CROSS SECTION AND AT LEAST ONE OF SAID LINKS BEING TUBULAR IN CROSS SECTION, A RESERVIOR VESSEL LOCATED IN THE SAME AMBIENT ENVIRONMENT AS A LINK SOLID IN CROSS SECTION SO THAT THE TEMPERATURE OF THE VESSEL IS IN SUBSTANTIAL EQUILIBRIUM WITH THAT OF SAID LINK SOLID IN CROSS SECTION, PUMP MEANS, AND CONDUIT MEANS CONNECTING SAID VESSEL, TUBULAR LINK AND PUMP TO FORM A CLOSED CIRCUIT FOR THE FLOW OF FLUID THERETHROUGH. 